A Problem about sidebar and border that I couldn't solve

Hi everyone : I came here to ask for help about a problem I met ,my english desn’t well enough , But i really need your kindly help . Let me describe it :

I now use the left sidemenu, and set a background image for the main interface , remove all the border,on ver4.4 above and my browser everything is normal, but on the ver below 4.4 ,it becomes that the border between sidemenu and pane can not be deleted .After I setted .pane{border:none !important;} ,the left has been deleted successfully , but it appears on the right side (Orz) .Then I setted *{border:none !important} ,it didn’t work .

Above is the problem I met , ask your help sincerely . :slight_smile:

Thanks a lot .